Vehicle occupant weight sensing systems are useful in connection with air bags and other pyrotechnically deployed restraints as a means of characterizing the occupant for purposes of determining whether to allow or suppress deployment of the restraints. In cases where an infant seat or child booster seat is placed on the seat cushion and cinched down with the seat belt, the presence of the infant or child seat can be detected based in part on a measure of the seat belt tension. However, in cases where the vehicle seat is equipped with a child seat anchoring system such as the LATCH (Lower Anchors and Tethers for CHildren) system, the infant or child seat can be secured using the seat anchors instead of the seat belt. Since tension applied to such child seat anchors produces an effect similar to that which occurs when the child seat is secured with the seat belt, it is desired to measure the tension exerted on such a child seat anchoring system.